In September 1944, Hudswell-Clarke and Co. Ltd and Hugh Wood Mining Co. reached an agreement to manufacture flameproofed diesel locos. Although not first in the field, the agreement actually produced the first operational 100 hp machine to pass the tests required to obtain certified approval for it to work underground.
The 102hp Huwood-Hudswell was an 0-6-0 fitted with a Gardner engine. Transmission was via a Vulcan Sinclair scoop controlled fluid coupling to a self changing 3-speed gearbox. On changing gear upwards the drive was maintained, preventing snatching at the drawbar. The original units were built with single cabs, though from 1951 some were equipped to work in tandem. In the 1950s, regulations were changed, requiring a cab to be fitted at each end. Our loco dates from 1954 and was originally in use at Seaham Colliery.